[Bug c/29613] New: static string in vararg function

[Bug c/29613] New: static string in vararg function

[etienne_lorrain at yahoo dot fr]

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When executing that on a target:
>>>>>>>>>>>>>>>>>>>>>>
#include <stdarg.h>

void bug_vsprintf( char *pString, const char *format, va_list ap)
{
        char c;
        char *str = 0;
        int str_cnt = 0;

        while((c = *format++) != '\0')
        {
                if (c == '%')
                {
                        if (*format++ == 's')
                        {
                                str = va_arg(ap, char *);
                                if (str == 0) str = "(null)";
                                for (str_cnt = 0; str[str_cnt] != '\0' &&
str_cnt <= 5; str_cnt++)
                                        continue;
                                if (str_cnt > 5) {
                                        static char errmsg[32] = "(invalid %s
ptr)";
                                        //char errmsg[32] = "(invalid %s ptr)";
// no bug
                                        str = errmsg;
                                        str_cnt = sizeof("(invalid %s ptr)") -
1;
                                        }
                        }


                        while(str_cnt)
                        {
                                *pString++ = (*str++);
                                str_cnt--;
                        }
                }
                else
                        *pString++ = c;
        }

        *pString = '\0';

}

void bug_sprintf( char *pString, const char *format, ...)
{
        va_list argptr;

        va_start( argptr, format );
        bug_vsprintf( pString, format, argptr );
        va_end( argptr );
}

void triggerbug(void)
{
        char buffer[50];
        bug_sprintf(buffer, "%s", "123456789");
        printf ("buggy buffer: %s i.e. 0x%X 0x%X 0x%X ...\r\n", buffer,
buffer[0], buffer[1], buffer[2]);
}

<<<<<<<<<<<<<
 (first include stdio.h for printf)
Compilation switch:
powerpc-eabi-gcc -Wall -W -O2 -fno-strict-aliasing -ffunction-sections
-std=gnu99 -Xassembler -mregnames bug.c

  I get the line:
buggy buffer: À i.e. 0xC0 0x0 0x57 ...
  If I remove the static (in "static char errmsg"), I get what I want:
buggy buffer: (invalid %s ptr) i.e. 0x28 0x69 0x6E ...


-- 
           Summary: static string in vararg function
           Product: gcc
           Version: 4.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: etienne_lorrain at yahoo dot fr
  GCC host triplet: cygwin-ia32
GCC target triplet: powerpc-eabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29613

[Bug target/29613] static string in vararg function

[etienne_lorrain at yahoo dot fr]

------- Comment #1 from etienne_lorrain at yahoo dot fr  2006-12-06 12:47 -------
 Was another problem (Initialise the main stack at the top of the reserved
space, without keeping two words safety linked to the calling convention,
so the first call would erase the first static variable at top_stack+4)
 Sorry.


-- 

etienne_lorrain at yahoo dot fr changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29613